分類Category
力、運動、能量、波與電。例子要算得回來，也要說清楚哪裡是假設。Forces, motion, energy, waves, and electricity. Examples should be checkable, and assumptions should be labeled.
「咖啡喝越多越矮」的調查圖，證明不了咖啡害人長不高。一起變化只叫相關，要說因果，得用控制變因的公平實驗。A chart showing coffee drinkers are shorter cannot prove coffee stunts growth. Changing together is correlation. To show cause, you need a fair test with controlled variables.
急轉彎時你滑向車門，不是被「離心力」往外推，而是身體想直走、車子往內轉。讓車轉彎的是指向圓心的靜摩擦力。In a sharp turn, no force throws you outward. Your body wants to go straight while the car turns in. Static friction toward the center makes the car turn.
特斯拉宣稱新 Roadster 0→60 mph 只要 0.81 秒，約 3.4 g。但輪胎摩擦力上限只有約 1 g——多出來的力從哪來？Tesla claims its new Roadster can go from 0 to 60 mph in 0.81 seconds. Tires alone would need about 2.7 seconds. The extra push is claimed to come from suction fans and cold-gas thrusters.
